The present invention relates to the field of intraluminal prostheses. More specifically, the present invention is directed to an intraluminal prosthesis which is adhesively bonded to the interior wall of a body conduit.
The use of tubular devices or conduits is well known in the repair or replacement of damaged or diseased lumens within the body. For example, tubular conduits are used to repair lumens such as in the esophagus and colon areas, and in particular, prostheses are used in the vascular system to repair, buttress or replace a weakened section of the vessel. It is well known in the field of vascular surgery to surgically replace a portion of a vessel with an endoprosthesis, such as a vascular graft. Such replacement procedures, however, generally involve invasive surgery, resulting in extensive recovery and high risk of infection and/or rejection.
More recently, the general trend in vascular surgery has moved toward less invasive techniques for repair of vessels. In order to minimize the recovery period and reduce the risk of infection and/or rejection, procedures have been developed for delivery and implantation of endoprostheses using minimally invasive procedures. Commonly, such procedures include intraluminal delivery involving percutaneous insertion of an endoprosthesis by way of a delivery catheter. Such endoprostheses include grafts which are generally in the form of a tubular lining provided for delivery within a section of a body conduit to treat the complications of atherosclerosis, i.e. arterial occlusion or aneurysms. These less invasive procedures permit delivery and implementation of an endoprosthesis without the need for replacement of a portion of the vessel, and thus eliminate major surgical intervention and the risks associated therewith. In order to secure a graft in place after delivery, it is common practice to employ a variety of mechanical securement means, for example sutures, staples and the like. Additionally, it is well known to employ a stent in combination with a graft in order to support and secure the graft in place within the body passageway after implantation. Stents are typically radially expandable and/or contractible support members which are positioned within a graft member or other tubular prosthesis. In common usage, after a prosthesis has been properly positioned, the stent is expanded to anchor the prosthesis within the body passageway. Natural cell growth through the wall of the prosthesis can then further anchor the prosthesis in place within the body lumen.
As can be appreciated, such mechanical securement means cannot effectively secure an endoprosthesis such as a graft continuously along the entire length thereof. Such mechanical securement can result in unsecured portions of the graft, thus resulting in gaps between the graft wall and the intraluminal wall of the vessel. Such gaps can result in an increased amount of cell growth necessary to anchor the prosthesis in place. Further, such mechanical securement can result in a bulky structure present within the lumen, which can inhibit normal flow through the lumen, and create a site for occlusion within the vessel.
Moreover, in recent years, polytetrafluoroethylene (PTFE) has become increasingly popular for use in such vascular graft applications due to its non-stick and inert properties. As can be appreciated, however, PTFE is difficult to adhere to vessel walls due to these inert properties.
Accordingly, a need exists for an implantable prosthesis which can be easily delivered to a repair site within a vessel, and can be effectively secured to the internal wall surface of the vessel along the length of the prosthesis to limit the gap between the prosthesis and the vessel wall.
It is an object of the present invention to provide an implantable prosthesis capable of effective securement within a body lumen.
It is a further object of the present invention to provide an implantable prosthesis which does not inhibit normal flow through the lumen.
These and other objects are attained through the present invention involving a prosthesis for implantation within a body lumen. The prosthesis includes a biocompatible elongate intraluminal liner having an interior surface and an exterior surface. A biocompatible adhesive is disposed on the exterior surface of the liner. The adhesive is active in an intraluminal environment so as to bond the exterior surface of the liner to an intraluminal surface of the body lumen.
The adhesive may be any type of adhesive known in the art which is capable of bonding in an intraluminal environment. Preferably, the adhesive is bioabsorbable, and may be a curable polymer adhesive such as photodynamically cured adhesives including ultraviolet light, temperature curing adhesives, or may be pressure sensitive adhesive. Particularly preferred adhesives include those selected from the group consisting of polyurethanes, cyanoacrylates, silicones, (meth)acrylates, and combinations thereof. The adhesive may also be a biological sealant capable of bonding the liner to the intraluminal surface, including biological sealants selected from the group consisting of fibrin, collagen, poly(L-glutamic acid), gelatin based hydrogel, N-vinyl pyrrolidone, and mixturesn a combinations thereof
In an alternate embodiment of the present invention, the adhesive is held within frangible encapsulants or nodules which are disposed on the exterior surface of the tubular body. The encapsulants are capable of rupturing when compressed between the tubular body and the lumen so as to release the adhesive, thereby bonding the exterior surface of the said liner to an intraluminal surface of the body lumen.
The liner preferably includes a plurality of pores sufficient to permit the ingrowth of body tissue. The adhesive may be disposed through at least one of these pores in the liner. Further, a mechanical support such as a radially expandable stent may be disposed along the interior surface of the tubular body to maintain the tubular body in an open position. The mechanical support may be removable from the tubular body, and may be bioabsorbable. The mechanical support may be any type of support known, such as porous polymeric band or a helically wound wire. Preferably, the mechanical support is positioned within at least one longitudinal end of the tubular body, most preferably at an upstream end of the tubular body, and may be provided at both longitudinal ends of the tubular body. The adhesive may extend through the pores of the liner and bond the mechanical support to the liner.
The liner may be in the form of a woven, knitted or braided textile tubular body, a spun filament tubular body, an extruded tube, or may be formed from a polymeric sheet. Preferably, the tubular body is formed from a material selected from the group consisting of polyesters, polypropylenes, polyethylenes, polyurethanes, polytetrafluoroethylenes, poly-alpha-hydroxy-acids, and combinations thereof. The liner may be a bioabsorbable material, but is more preferentially a biologically inert material, such as polytetrafluoroethylene (PTFE). The liner may expandable from an insertion diameter to an implantation diameter which is greater than the insertion diameter so that at the implantation diameter the liner is conformable to the intraluminal surface of the body lumen.
In alternate embodiments, the prosthesis further includes a removable cover over the adhesive for delivery, and may include a concentric tubular body within the liner. In such embodiments, the mechanical support is preferably positioned between the concentric tubular body and the liner.
In a further embodiment of the present invention, a method of adhering an intraluminal liner to a venal wall is provided. The method includes providing a prosthesis including an intraluminal liner having a biocompatible adhesive active in an intraluminal environment disposed on an exterior surface thereof; delivering the prosthesis to an area of implantation; and expanding the prosthesis so as to cause the adhesive to contact an interior surface of the venal wall, thereby causing the adhesive to bond the prosthesis to the venal wall.